Can also be purchased at Amazon.ca and other outlets.
Sky and Telescope's "Pocket Sky Atlas" is a wonderful resource for all amateur astronomers. These challenges are designed for spicing up your observing.
Sky and Telescope Magazine's "Pocket Sky Atlas" has found a place in the tool kit of many amateur astronomers. The convenient size makes it easy to use at the telescope without requiring a separate chart table. For urban astronomers, the charts are sufficient for the brighter stars visible under urban skies; the charts offer enough detail for star hops with telescopes or binoculars. When taking advantage of a dark sky location, the details of the charts allow for hours of wanderings per page depending on the size of the telescope and the skill of the operator.
The challenge objects are indexed to the star chart pages containing those objects. The idea is to have fun and perhaps expand your observing past the "usual suspects" that can be found because of past experiences. Seeing conditions may not allow finding these objects every night, but they should be visible at some point during the month.